1. Field of the Invention
The present invention relates to an electronic display unit such as a navigation system mounted in an automotive vehicle.
2. Description of the Prior Art
In the past, an automotive navigation system which is an electronic display unit has been adapted such that a motor is driven by operating a control switch provided on a front surface thereof and the rotation of the motor is transferred by gears to a unit body which in turn rotates through a predetermined angle.
The motor is controlled to rotate at a constant speed and, accordingly, the unit body rotates at a constant speed.
The reason for rotating the unit body as above described is that it is necessary to effectively utilize, in particular, the rear space of this type of unit body which is commonly embedded in a center console within the automotive vehicle. The unit body is required to be minimized in size in terms of layout of the unit body itself. However, a display screen of an LCD and the like is not permitted to be very small in size in order to ensure visibility.
The prior art navigation system rotates at a constant speed as above described. Rotation at a very high speed is disadvantageous in that, as soon as the control switch on the front surface of the unit body is operated, the unit body starts rotating to strike user's fingers. For this reason, so high speed of rotation is impractical, resulting in some users feeling that the rotation requires too much time.
One approach for ensuring the operability of the control switch independent of the speed of rotation of the unit body is to provide an additional non-rotatable control panel on which the switch is disposed. The provision of such a control panel increases the entire size of the display unit. As above stated, it is necessary to avoid the increased size of the unit body since it is disposed in the center console. In addition, the entire size reduction is required while the size of the display screen of the LCD is sufficiently ensured. For these reasons, the control switch is required to be disposed on the front surface of the unit body.